Electric furnace.



No. 628,373. 'Patented my 4, 1899.

F. P. VAN DENBERGH. v

ELECTRIC N E.

(Application file 896.)

(No llode.) 2 Sheets-Sheet I.

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Patented July 4, |899.

F. P. VAN D ENBERGH. ELECTRIC FURNACE.

' (Application ledJan. 15, 1896,.)

2 Sheets-Sheet 2.

(No Model.)

UNITED STATES PATENT OFFICE.

FRANK P. VAN DENBERGI-I, OF BUFFALO, NEXV YORK.`

ELECTRIC FU RNACE.

SPECIFICATION forming part of Letters Patent No. 628,378, dated July 4,1899.

Application tiled January 15, 1896. Serial No. 575,626. (No model.)

To @ZZ whom t may con/cern:

Beit known that I, FRANK l?. VAN DEN- BERGH, a citizen of the UnitedStates, residing at Buffalo, in the county of Erie and State of NewYork, have invented a new and useful Improvement in Electric Furnaces,of which the following is a full', clear, andexact description.

My invention relates to an improvementin electric furnaces, and moreparticularly to a furnace for the purpose of reducing ores and othermaterials.

The object of my invention is to employ heat produced by electric energyin direct contact with the material and to provide means whereby heat soproduced may be rendered efficient in the continuous and economicaldecomposition of a wide range of minerals and other substances,particularly those of ahighly-refractory nature. In order that such endmaybe attained,I provide a furnace simple, cheap, and readily repaired,means for regulating the length of the arc and also means for adjustingthe position of the arc with reference to the material or charge withinthe furnace, a system of continuous feed capable of accurate regulation,means for carrying the gases and vapors to a condenser, and means forregulating and maintaining a uniform level of the liquefied mass in thefurnace and a continuous removal of the same while the furnace is inoperation, and means for maintaining a substantially uniform andconstant thermal action for the purpose of securing a complete andexhaustive reduction.

As stated, my invention is adapted to use in awide range of reductionprocesses. Typical processes would be such as the production ofphosphoric acid from apatite or other phosphoric substances, theproduction of sulfuric acid from gypsum or other material containingsulfur or its compounds or the reduction of cinnabar ores, or thereduction of such materials as the alkaline chlorids and bromids, and Ido not limit myself to any one process or the production of any oneproduct. For this reason the drawings herewith are diagrammatic incharacter, leaving it to the person skilled in the art to adapt, throughmechanical skill, the general principles to the specific use in hand.

Referring to the drawings herewith, in

which like letters referto like parts throughout the drawings, Figure lis a longitudinal vertical section, and Fig. 2 la transverse verticalsection, of myinvention. Fig. 3 is a detail cross-sectional view,enlarged, of a holder for a flat electrode.v Fig. 4 is an insideelevation of the same.y Figs. 5 and 6 are views similar to Figs. 3 and4, illustrating another form of electrode-holder.

" A is the main body of the furnace, which may be made in any desiredform and of any desirable heat-resisting material. Preferably this bodyshould be built'up of a lireclay or other refractory material thoroughlyluted, and it is desirable at times to line the upper portion of thechamber with a heatresistant, as shown at B, to further prevent theescape of gas or vapor. It is also desirable that the lower crucibleportion of' the chamber should be somewhat reduced in cross-section inorder that a less quantity of liquefied material may be retained withoutreducing the depth of the crucible. The base of the crucible O should bereadily removable, and in the drawings I have indicated one simplemethod-that of having the base C flanged, so as to engage closely withthe body A, and blocking the same in place with brick D D.

E E are electrodes connecting, respectively, with the positive andnegative poles of a source of electric energy. These electrodes shouldbe mounted slidably within bearings F, so that they may be inserted orwithdrawn to regulate the length of the arc, and they should also bemounted so that the inner ends may be raised or lowered with referenceto the mass within the chamber independent of the axial or endwisemovement of the electrodes. The bearings F, in vwhich the electrodes aremounted, are close-fitting, so that the vapors within the furnace shallnot escape at such places, and they are preferably round incross-section and so mounted that they may turn with the electrodes asthe latter are moved. The dotted lines G, Fig. 1, indicate positions towhich the electrodes may be moved.

The bearings F for the electrodes are constructed of iron or othersuitable metal and are round in cross-section and perforated for IOO thepassage of the electrodes, as at f. These bearings will be properlyinsulated, as by means of sheets or plates of mica, and are mounted insupporting boxes or brackets F, in which the bearings iit withsufficient tightness to prevent the escape of the vapors formed withinthe furnace and yet allow the bearings to be turned to change thepositions of the electrodes. The boxes or brackets F are secured to therefractory walls of the furnace, being provided with flanges f" for thatpurpose, in such positions that they and the bearings F are notsubjected directly to the intense heat generated within thefurnace-chamber, the furnace-walls being perforated, as at a, to permitthe passage of the electrodes from their bearings into thefurnace-chamber.

In Figs. 3 and -t there is illustrated a holder or bearing for a broadfiat electrode and in Figs. 5 and 6 a bearing for a round electrode. Thebearing F (shown in Figs. 3 and et) is cylindrical in shape and can onlyturn on its longitudinal axis, so the electrode is adjustable only inthe arc of a circle, except as it is adjustable in the direction of itslength by being slid bodily within its bearing. The bearing shown inFigs. 5 and G is globular in shape, so that the electrode which itcarries may be adj usted in any direction.

The top of the chamber may be closed in any desired manner, but amovable cap I-I, as shown, is preferable. Through this top. is an inletI, through which the material to be treated, properly combined with aflux or such other agent or agents as may be required, is introduced.The material is fed into the inlet from a feed-reservoir J, closed atthe top and bottom by valves K and L, by any one of the well-known feedmechanisms, such as the cylinder and piston M, as shown, actuated by aneccentric and pulley N, belted to a source of power providing aregulatable feed.

The feeding device just described and which is illustrated in thedrawings operates to seal the furnace-chamber against the escape ofgases at this place by reason of the packing of the material being fedin the cylinder M.

' It will be observed that the feeding device is arranged directly abovethe electrodes, so that the material as it is fed into the chamber ofthe furnace falls directly into the electric arc between the electrodes.

The feed-reservoir should connect, through the valve K, with astorage-reservoir which contains the supply, and by closing the valve Land opening the valve K the feed-reservoir may be filled without anybacking up of fumes or gases.

R is an outlet-pipe connecting with a condensingchamber constructed tomeet the needs of the process in use.

O is an opening leading from the base of the crucible and passing upwardwithin the body of the furnace A and then to an exit P. It is evidentthat the height of this exit will determine the level of the liquid masswithin the Crucible, as indicated by the broken line Q, and it is clearto one skilled in the art that this exit may be readily changed to meetthe demands of the process. Itis advisable that this means of egress forthe liquid mass should lead from the bottom, so as to remove thematerial which has been most effectively treated, and it is particularlyimportant that the conduit to the exit P should be adjacent (as in theconstruction shown) to the furnace-chainber in order that the heat fromthe body of the furnace may insure perfect liquefaction and consequentfree flow of the material being drawn off.

The electrodes enter the furnace-chamber at a height above the level atwhich the mass of liquefied Amaterial being treated stands, so that thearc between the electrodes is above the liquid mass. This is mostimportant, because if the electrodes are within the fluid mass theworking value of the electric arc will be so impaired by reducedresistance in the mass that practically no result on refractorysubstances would be obtained.

The residuum-exit is free, so that the discharge may be continuous, andits opening O into the crucible is situated at a level much below thepoint where the electric arc is most active, so that the material isthoroughly reduced before it passes out of the crucible. Vere theelectrodes situated within the Huid mass, especially were one or both ofthem below the level of the residuum-exit, danger and loss would arisewhen the process was working continuously from the passage of gasesalong with the residuum. This l avoid by the construction andarrangement of the parts of the furnace as described.

In operation the furnace is charged, the electrodes raised and broughtnear together, the current applied, and the product slowly fed in. Asthe resistance of the mass reduces with fusion the electrodes should beretracted, and as the fusion increases depressed to the most effectivepoint of operation. The gases or vapors iill the chambers and are forcedout through the outlet-pipe R to the condenser. The feed becomescontinuous, rapid, and complete, and the liquefied mass rises to thelevel G, and it is continuously carried off through the opening and exitO, and thus the process becomes continuous and for all practicalpurposes self-regulating.

Having thus described my invention, what I claim is, without limitingmyself to the specie mechanism shownl. An electric furnace, comprising afeeding device, electrodes, adjustable lengthwise with reference to eachother to vary the length of the arc, and also provided with meanswhereby the inner ends of the electrodes are vertically movable,independent of the said lengthwise adjustment, to change the position ofthe are with reference to the mass of material being treated,avapor-exit and a residuum-exit, substantially as set forth.

2. In an electric furnace, a close furnacechamber having a vapor-exit, acrucible hav- ICO IIO

IZO

ing a free residuum-exit leading from its lower portion and dischargingat a higher level than the crucible, a continuous-feed mechanism, andelectrodes adj ustablelengthwise with reference to each other to varythe length of the arc, and also adjustable verti.

cally, at their inner ends, independent of the said lengthwiseadjustment, substantially as set forth.

3. In an electric furnace, the combination with the body of the furnacehaving refractory walls, of the electrodes which extend through thewalls of the furnace into the furnacechamber, the electrodes beingadjustable toward and from each other in the direction of their length,and also adjustable so that the inner ends of the electrodes may beraised or lowered with reference to the mass Within the furnace withoutat the Same time adjusting them in the direction of their length,substantially as set forth.

4. An electric furnace comprising the following elemenls: viz., theelectrodes, adjustable in the direction of their length, and alsovertically adjustable within the furnacechamber independent of theiradjustment in the direction of their length, an automatic, regulatablefeeding mechanism, a vapor-exit, and a residuum-exit leading from thelower part of the furnace-chamber, and discharging at the level which itis desired the fluid mass within the furnace should maintain,substantially as set forth.

5. In an electric furnace, the combination with the body of a furnacehaving refractory walls, of the electrodes, and the bearings for theelectrodes, each round in a cross-section, taken on a line correspondingWith the longitudinal center of the electrode,and mounted within theWalls of the furnace so as to be free to turn therein to a limitedextent, substantially as set forth.

In testimony that I claim the invention above set forth I affix mysignature in presence of two witnesses.

FRANK P. VAN DENBERGH.

Witnesses:

EDWARD R. BosBY, CHARLES M. HUGHsoN.

